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Wrox professional aspnet_mvc4

  1. 1. ffirs.indd iiffirs.indd ii 9/11/2012 3:00:11 PM9/11/2012 3:00:11 PM
  2. 2. PROFESSIONAL ASP.NET MVC 4 FOREWORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xxvii INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . xxix CHAPTER 1 Getting Started. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 CHAPTER 2 Controllers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31 CHAPTER 3 Views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 CHAPTER 4 Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71 CHAPTER 5 Forms and HTML Helpers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 CHAPTER 6 Data Annotations and Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .119 CHAPTER 7 Membership, Authorization, and Security . . . . . . . . . . . . . . . . . . . . . . . . .137 CHAPTER 8 Ajax. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 CHAPTER 9 Routing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 221 CHAPTER 10 NuGet. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 249 CHAPTER 11 ASP.NET Web API . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 279 CHAPTER 12 Dependency Injection. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297 CHAPTER 13 Unit Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341 CHAPTER 14 Extending MVC. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 CHAPTER 15 Advanced Topics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365 CHAPTER 16 Real-World ASP.NET MVC: Building the NuGet.org Website. . . . . . . . 423 INDEX. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 443 ffirs.indd iffirs.indd i 9/11/2012 3:00:11 PM9/11/2012 3:00:11 PM
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  4. 4. PROFESSIONAL ASP.NET MVC 4 ffirs.indd iiiffirs.indd iii 9/11/2012 3:00:11 PM9/11/2012 3:00:11 PM
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  6. 6. PROFESSIONAL ASP.NET MVC 4 Jon Galloway Phil Haack Brad Wilson K. Scott Allen ffirs.indd vffirs.indd v 9/11/2012 3:00:11 PM9/11/2012 3:00:11 PM
  7. 7. Professional ASP.NET MVC 4 Published by John Wiley & Sons, Inc. 10475 Crosspoint Boulevard Indianapolis, IN 46256 www.wiley.com Copyright © 2012 by John Wiley & Sons, Inc., Indianapolis, Indiana Published simultaneously in Canada ISBN: 978-1-118-34846-8 ISBN: 978-1-118-42432-2 (ebk) ISBN: 978-1-118-41675-4 (ebk) ISBN: 978-1-118-43404-8 (ebk) Manufactured in the United States of America 10 9 8 7 6 5 4 3 2 1 No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, elec- tronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through pay- ment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permissions. Limit of Liability/Disclaimer of Warranty: The publisher and the author make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation warranties of fitness for a particular purpose. No warranty may be created or extended by sales or promotional materials. The advice and strategies contained herein may not be suitable for every situation. This work is sold with the understanding that the publisher is not engaged in rendering legal, accounting, or other professional services. If professional assistance is required, the services of a competent professional person should be sought. Neither the publisher nor the author shall be liable for damages arising herefrom. The fact that an organization or Web site is referred to in this work as a citation and/or a potential source of further information does not mean that the author or the publisher endorses the information the organization or Web site may provide or recommendations it may make. Further, readers should be aware that Internet Web sites listed in this work may have changed or disappeared between when this work was written and when it is read. For general information on our other products and services please contact our Customer Care Department within the United States at (877) 762-2974, outside the United States at (317) 572-3993 or fax (317) 572-4002. Wiley publishes in a variety of print and electronic formats and by print-on-demand. Some material included with standard print versions of this book may not be included in e-books or in print-on-demand. If this book refers to media such as a CD or DVD that is not included in the version you purchased, you may download this material at http://booksupport.wiley.com. For more information about Wiley products, visit www.wiley.com. Library of Congress Control Number: 9781118348468 Trademarks: Wiley, the Wiley logo, Wrox, the Wrox logo, Programmer to Programmer, and related trade dress are trademarks or registered trademarks of John Wiley & Sons, Inc. and/or its affiliates, in the United States and other countries, and may not be used without written permission. All other trademarks are the property of their respective owners. John Wiley & Sons, Inc., is not associated with any product or vendor mentioned in this book. ffirs.indd viffirs.indd vi 9/11/2012 3:00:13 PM9/11/2012 3:00:13 PM
  8. 8. To my wife, Rachel, my daughters, Rosemary, Esther, and Ellie, and to you for reading this book. Enjoy! —Jon Galloway My wife, Akumi, deserves to have her name on the cover as much as I do, for all her support made this possible. And thanks to Cody for his infectious happiness. —Phil Haack To Potten on Potomac. —K. Scott Allen ffirs.indd viiffirs.indd vii 9/11/2012 3:00:13 PM9/11/2012 3:00:13 PM
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  10. 10. ABOUT THE AUTHORS JON GALLOWAY works at Microsoft as a Windows Azure Technical Evangelist focused on the ASP .NET platform. He wrote the MVC Music Store tutorial, helped organize mvcConf and aspConf (free online conferences for the ASP.NET community), and speaks at conferences and Web Camps worldwide. He also has worked in a wide range of web development shops, from scrappy startups to large financial companies. He’s part of the Herding Code podcast (http://herdingcode.com), blogs at http://weblogs.asp.net/jgalloway, and twitters as @jongalloway. He lives in San Diego with his wife, three daughters, and a bunch of avocado trees. PHIL HAACK works at GitHub, striving to make Git and GitHub better for developers on Windows. Prior to joining GitHub, Phil was a Senior Program Manager with the ASP.NET team whose areas of responsibility included ASP.NET MVC and NuGet. As a code junkie, Phil loves to craft software. Not only does he enjoy writing software, he enjoys writing about software and software manage- ment on his blog, http://haacked.com/. BRAD WILSON works for Microsoft as a Senior Software Developer on the Azure Application Platform and Tools team on the ASP.NET MVC and Web API projects. Prior to ASP.NET, Brad also worked on the CodePlex and the Patterns and Practices teams at Microsoft, and has acted as a developer, consultant, architect, team lead, and CTO at various software companies for nearly 20 years. He’s the co-author of the xUnit.net open source developer testing framework, maintains a blog focused primarily on ASP.NET topics at http://bradwilson.typepad.com/, and tweets as @bradwilson. Brad lives in beautiful Redmond, Washington. K. SCOTT ALLEN is the founder of OdeToCode LLC and a software consultant. Scott has 20 years of commercial software development experience across a wide range of technologies. He has delivered software products for embedded devices, Windows desktop, web, and mobile platforms. He has developed web services for Fortune 50 companies and firmware for startups. Scott is also a speaker at international conferences and delivers classroom training and mentoring to companies around the world. ffirs.indd ixffirs.indd ix 9/11/2012 3:00:13 PM9/11/2012 3:00:13 PM
  11. 11. ABOUT THE TECHNICAL EDITOR EILON LIPTON joined the ASP.NET team as a developer at Microsoft in 2002. On this team, he has worked on areas ranging from data source controls to localization to the UpdatePanel control. That team is now part of the Azure Application Platform Team, where Eilon is the principal development manager for ASP.NET MVC, ASP.NET Web API, and Entity Framework. Eilon is also a speaker on a variety of ASP.NET-related topics at conferences worldwide. He graduated from Boston University with a dual degree in Math and Computer Science. In his spare time Eilon spends time in his garage workshop building what he considers to be well-designed furniture. If you know anyone who needs a coffee table that’s three feet tall and has a slight slope to it, send him an e-mail. ffirs.indd xffirs.indd x 9/11/2012 3:00:13 PM9/11/2012 3:00:13 PM
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  14. 14. ACKNOWLEDGMENTS THANKS TO FAMILY AND FRIENDS who graciously acted as if “Jon without sleep” is someone you’d want to spend time with. Thanks to the whole ASP.NET team for making work fun since 2002, and especially to Brad Wilson and Phil Haack for answering tons of random questions. Thanks to Warren G. Harding for normalcy. Thanks to Philippians 4:4–9 for continually reminding me which way is up. — Jon Galloway THANKS GO TO MY LOVELY WIFE, Akumi, for her support, which went above and beyond all expec- tations and made this possible. I’d like to also give a shout out to my son, Cody, for his sage advice, delivered as only a two-year-old can deliver it. I’m sure he’ll be embarrassed 10 years from now that I used such an anachronism (“shout out”) in my acknowledgment to him. Thanks go to my daugh- ter, Mia, as her smile lights up the room like unicorns. — Phil Haack ffirs.indd xiiiffirs.indd xiii 9/11/2012 3:00:13 PM9/11/2012 3:00:13 PM
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  16. 16. CONTENTS FOREWORD xxvii INTRODUCTION xxix CHAPTER 1: GETTING STARTED 1 A Quick Introduction to ASP.NET MVC 1 How ASP.NET MVC Fits in with ASP.NET 2 The MVC Pattern 2 MVC as Applied to Web Frameworks 3 The Road to MVC 4 3 ASP.NET MVC 1 Overview 4 ASP.NET MVC 2 Overview 4 ASP.NET MVC 3 Overview 5 MVC 4 Overview 10 ASP.NET Web API 10 Enhancements to Default Project Templates 11 Mobile Project Template using jQuery Mobile 13 Display Modes 14 Bundling and Minification 14 Included Open Source Libraries 15 Miscellaneous Features 15 Open Source Release 17 Creating an MVC 4 Application 17 Software Requirements for ASP.NET MVC 4 17 Installing ASP.NET MVC 4 18 Installing the MVC 4 Development Components 18 Installing MVC 4 on a Server 18 Creating an ASP.NET MVC 4 Application 19 The New ASP.NET MVC 4 Dialog 20 Application Templates 20 View Engines 22 Testing 22 The MVC Application Structure 24 ASP.NET MVC and Conventions 27 Convention over Configuration 28 Conventions Simplify Communication 29 Summary 29 ftoc.indd xvftoc.indd xv 9/11/2012 2:59:44 PM9/11/2012 2:59:44 PM
  17. 17. xvi CONTENTS CHAPTER 2: CONTROLLERS 31 The Controller’s Role 31 A Sample Application: The MVC Music Store 34 Controller Basics 36 A Simple Example: The Home Controller 37 Writing Your First Controller 40 Creating the New Controller 40 Writing Your Action Methods 42 A Few Quick Observations 43 Parameters in Controller Actions 43 Summary 46 CHAPTER 3: VIEWS 47 The Purpose of Views 48 Specifying a View 49 ViewData and ViewBag 51 Strongly Typed Views 52 View Models 54 Adding a View 54 Understanding the Add View Dialog Options 55 The Razor View Engine 57 What Is Razor? 57 Code Expressions 59 HTML Encoding 61 Code Blocks 62 Razor Syntax Samples 63 Implicit Code Expression 63 Explicit Code Expression 63 Unencoded Code Expression 64 Code Block 64 Combining Text and Markup 64 Mixing Code and Plain Text 65 Escaping the Code Delimiter 65 Server-Side Comment 65 Calling a Generic Method 66 Layouts 66 ViewStart 69 Specifying a Partial View 69 Summary 70 ftoc.indd xviftoc.indd xvi 9/11/2012 2:59:44 PM9/11/2012 2:59:44 PM
  18. 18. xvii CONTENTS CHAPTER 4: MODELS 71 Modeling the Music Store 72 Scaffolding a Store Manager 74 What Is Scaffolding? 74 Empty Controller 75 Controller with Empty Read/Write Actions 75 API Controller with Empty Read/Write Actions 75 Controller with Read/Write Actions and Views, Using Entity Framework 75 Scaffolding and the Entity Framework 76 Code First Conventions 77 The DbContext Class 77 Executing the Scaffolding Template 78 The Data Context 79 The StoreManagerController 79 The Views 81 Executing the Scaffolded Code 82 Creating Databases with the Entity Framework 82 Using Database Initializers 83 Seeding a Database 84 Editing an Album 86 Building a Resource to Edit an Album 86 Models and View Models Redux 88 The Edit View 88 Responding to the Edit POST Request 89 The Edit Happy Path 90 The Edit Sad Path 90 Model Binding 91 The DefaultModelBinder 91 Explicit Model Binding 92 Summary 94 CHAPTER 5: FORMS AND HTML HELPERS 95 Using Forms 95 The Action and the Method 96 To GET or to POST? 97 Searching for Music with a Search Form 97 Searching for Music by Calculating the Action Attribute Value 99 HTML Helpers 100 Automatic Encoding 100 ftoc.indd xviiftoc.indd xvii 9/11/2012 2:59:45 PM9/11/2012 2:59:45 PM
  19. 19. xviii CONTENTS Making Helpers Do Your Bidding 101 Inside HTML Helpers 102 Setting Up the Album Edit Form 102 Html.BeginForm 102 Html.ValidationSummary 103 Adding Inputs 103 Html.TextBox and Html.TextArea 104 Html.Label 105 Html.DropDownList and Html.ListBox 105 Html.ValidationMessage 107 Helpers, Models, and View Data 107 Strongly Typed Helpers 109 Helpers and Model Metadata 110 Templated Helpers 111 Helpers and ModelState 112 Other Input Helpers 112 Html.Hidden 112 Html.Password 112 Html.RadioButton 113 Html.CheckBox 113 Rendering Helpers 113 Html.ActionLink and Html.RouteLink 114 URL Helpers 114 Html.Partial and Html.RenderPartial 115 Html.Action and Html.RenderAction 116 Passing Values to RenderAction 117 Cooperating with the ActionName Attribute 117 Summary 118 CHAPTER 6: DATA ANNOTATIONS AND VALIDATION 119 Annotating Orders for Validation 120 Using Validation Annotations 122 Required 122 StringLength 122 RegularExpression 123 Range 123 Validation Attributes from System.Web.Mvc 124 Custom Error Messages and Localization 125 Looking behind the Annotation Curtain 125 Validation and Model Binding 126 Validation and Model State 126 ftoc.indd xviiiftoc.indd xviii 9/11/2012 2:59:45 PM9/11/2012 2:59:45 PM
  20. 20. xix CONTENTS Controller Actions and Validation Errors 127 Custom Validation Logic 128 Custom Annotations 129 IValidatableObject 132 Display and Edit Annotations 133 Display 133 ScaffoldColumn 134 DisplayFormat 134 ReadOnly 134 DataType 135 UIHint 135 HiddenInput 135 Summary 135 CHAPTER 7: MEMBERSHIP, AUTHORIZATION, AND SECURITY 137 Using the Authorize Attribute to Require Login 139 Securing Controller Actions 140 How the AuthorizeAttribute Works with Forms Authentication and the AccountController 143 Windows Authentication in the Intranet Application Template 145 Securing Entire Controllers 146 Securing Your Entire Application Using a Global Authorization Filter 147 Using the Authorize Attribute to Require Role Membership 148 Extending Roles and Membership 149 External Login via OAuth and OpenID 150 Registering External Login Providers 150 Configuring OpenID Providers 152 Configuring OAuth Providers 155 Security Implications of External Logins 155 Trusted External Login Providers 155 Require SSL for Login 156 Understanding the Security Vectors in a Web Application 157 Threat: Cross-Site Scripting 157 Threat Summary 157 Passive Injection 157 Active Injection 160 Preventing XSS 162 Threat: Cross-Site Request Forgery 167 Threat Summary 167 Preventing CSRF Attacks 169 Threat: Cookie Stealing 171 ftoc.indd xixftoc.indd xix 9/11/2012 2:59:45 PM9/11/2012 2:59:45 PM
  21. 21. xx CONTENTS Threat Summary 171 Preventing Cookie Theft with HttpOnly 172 Threat: Over-Posting 172 Threat Summary 173 Preventing Over-Posting with the Bind Attribute 174 Threat: Open Redirection 175 Threat Summary 175 Protecting Your ASP.NET MVC 1 and MVC 2 Applications 179 Taking Additional Actions When an Open Redirect Attempt Is Detected 182 Open Redirection Summary 183 Proper Error Reporting and the Stack Trace 183 Using Configuration Transforms 184 Using Retail Deployment Configuration in Production 185 Using a Dedicated Error Logging System 185 Security Recap and Helpful Resources 185 Summary 187 CHAPTER 8: AJAX 189 jQuery 190 jQuery Features 190 The jQuery Function 190 jQuery Selectors 192 jQuery Events 192 jQuery and Ajax 193 Unobtrusive JavaScript 193 Using jQuery 194 Custom Scripts 195 Placing Scripts in Sections 195 The Rest of the Scripts 196 Ajax Helpers 196 Ajax ActionLinks 197 HTML 5 Attributes 199 Ajax Forms 200 Client Validation 202 jQuery Validation 202 Custom Validation 203 IClientValidatable 204 Custom Validation Script Code 205 Beyond Helpers 207 jQuery UI 208 Autocomplete with jQuery UI 209 ftoc.indd xxftoc.indd xx 9/11/2012 2:59:45 PM9/11/2012 2:59:45 PM
  22. 22. xxi CONTENTS Adding the Behavior 210 Building the Data Source 210 JSON and Client-Side Templates 212 Adding Templates 212 Modifying the Search Form 213 Getting JSON 214 jQuery.ajax for Maximum Flexibility 216 Improving Ajax Performance 217 Using Content Delivery Networks 217 Script Optimizations 217 Bundling and Minification 218 Summary 219 CHAPTER 9: ROUTING 221 Uniform Resource Locators 222 Introduction to Routing 223 Comparing Routing to URL Rewriting 223 Defining Routes 224 Route URLs 224 Route Values 226 Route Defaults 227 Route Constraints 230 Named Routes 231 MVC Areas 233 Area Route Registration 233 Area Route Conflicts 234 Catch-All Parameter 234 Multiple URL Parameters in a Segment 235 StopRoutingHandler and IgnoreRoute 236 Debugging Routes 237 Under the Hood: How Routes Generate URLs 239 High-Level View of URL Generation 239 A Detailed Look at URL Generation 240 Ambient Route Values 242 Overflow Parameters 244 More Examples of URL Generation with the Route Class 244 Under the Hood: How Routes Tie Your URL to an Action 245 The High-Level Request Routing Pipeline 246 RouteData 246 Custom Route Constraints 246 Using Routing with Web Forms 247 Summary 248 ftoc.indd xxiftoc.indd xxi 9/11/2012 2:59:45 PM9/11/2012 2:59:45 PM
  23. 23. xxii CONTENTS CHAPTER 10: NUGET 249 Introduction to NuGet 249 Installing NuGet 250 Adding a Library as a Package 252 Finding Packages 252 Installing a Package 254 Updating a Package 256 Recent Packages 257 Package Restore 257 Using the Package Manager Console 259 Creating Packages 262 Packaging a Project 262 Packaging a Folder 263 NuSpec File 263 Metadata 264 Dependencies 266 Specifying Files to Include 267 Tools 268 Framework and Profile Targeting 271 Prerelease Packages 272 Publishing Packages 272 Publishing to NuGet.org 273 Using NuGet.exe 274 Using the Package Explorer 275 Summary 278 CHAPTER 11: ASP.NET WEB API 279 Defining ASP.NET Web API 280 Getting Started with Web API 280 Writing an API Controller 281 Examining the Sample ValuesController 282 Async by Design: IHttpController 283 Incoming Action Parameters 284 Action Return Values, Errors, and Asynchrony 284 Configuring Web API 285 Configuration in Web-Hosted Web API 286 Configuration in Self-Hosted Web API 286 Configuration in Third-Party Hosts 287 Adding Routes to Your Web API 287 Binding Parameters 288 ftoc.indd xxiiftoc.indd xxii 9/11/2012 2:59:45 PM9/11/2012 2:59:45 PM
  24. 24. xxiii CONTENTS Filtering Requests 290 Enabling Dependency Injection 291 Exploring APIs Programmatically 292 Tracing the Application 293 Web API Example: ProductsController 293 Summary 296 CHAPTER 12: DEPENDENCY INJECTION 297 Software Design Patterns 297 Design Pattern: Inversion of Control 298 Design Pattern: Service Locator 300 Strongly Typed Service Locator 300 Weakly Typed Service Locator 301 The Pros and Cons of Service Locators 304 Design Pattern: Dependency Injection 304 Constructor Injection 304 Property Injection 305 Dependency Injection Containers 306 Dependency Resolution in MVC 307 Singly Registered Services in MVC 308 Multiply Registered Services in MVC 309 Arbitrary Objects in MVC 311 Creating Controllers 311 Creating Views 312 Dependency Resolution in Web API 313 Singly Registered Services in Web API 314 Multiply Registered Services in Web API 315 Arbitrary Objects in Web API 316 Dependency Resolvers in MVC vs. Web API 316 Summary 316 CHAPTER 13: UNIT TESTING 317 The Meaning of Unit Testing and Test-Driven Development 318 Defining Unit Testing 318 Testing Small Pieces of Code 318 Testing in Isolation 318 Testing Only Public Endpoints 319 Automated Results 319 Unit Testing as a Quality Activity 319 Defining Test-Driven Development 320 The Red/Green Cycle 320 ftoc.indd xxiiiftoc.indd xxiii 9/11/2012 2:59:45 PM9/11/2012 2:59:45 PM
  25. 25. xxiv CONTENTS Refactoring 321 Structuring Tests with Arrange, Act, Assert 321 The Single Assertion Rule 322 Creating a Unit Test Project 322 Examining the Default Unit Tests 323 Test Only the Code You Write 327 Tips and Tricks for Unit Testing ASP.NET MVC Applications 328 Testing Controllers 328 Keeping Business Logic out of Your Controllers 328 Passing Service Dependencies via Constructor 329 Favoring Action Results over HttpContext Manipulation 330 Favoring Action Parameters over UpdateModel 331 Using Action Filters for Orthogonal Activities 332 Testing Routes 333 Testing Calls to IgnoreRoute 333 Testing Calls to MapRoute 334 Testing Unmatched Routes 335 Testing Validators 335 Summary 339 CHAPTER 14: EXTENDING MVC 341 Extending Models 342 Turning Request Data into Models 342 Exposing Request Data with Value Providers 342 Creating Models with Model Binders 343 Describing Models with Metadata 348 Validating Models 350 Extending Views 354 Customizing View Engines 354 Writing HTML Helpers 356 Writing Razor Helpers 357 Extending Controllers 358 Selecting Actions 358 Choosing Action Names with Name Selectors 358 Filtering Actions with Method Selectors 358 Action Filters 359 Authorization Filters 360 Action and Result Filters 360 Exception Filters 361 Providing Custom Results 361 Summary 363 ftoc.indd xxivftoc.indd xxiv 9/11/2012 2:59:45 PM9/11/2012 2:59:45 PM
  26. 26. xxv CONTENTS CHAPTER 15: ADVANCED TOPICS 365 Mobile Support 365 Adaptive Rendering 366 The Viewport Meta Tag 368 Adaptive Styles Using CSS Media Queries 368 Display Modes 370 Layout and Partial View Support 371 Custom Display Modes 371 Mobile Site Template 372 Advanced Razor 373 Templated Razor Delegates 373 View Compilation 374 Advanced View Engines 376 Configuring a View Engine 377 Finding a View 377 The View Itself 378 Alternative View Engines 380 New View Engine or New ActionResult? 381 Advanced Scaffolding 381 Customizing T4 Code Templates 382 The MvcScaffolding NuGet Package 383 Updated Add Controller Dialog Options 383 Using the Repository Template 384 Adding Scaffolders 386 Additional Resources 386 Advanced Routing 386 RouteMagic 387 Editable Routes 387 Advanced Templates 391 The Default Templates 392 MVC Futures and Template Definitions 392 Template Selection 395 Custom Templates 396 Advanced Controllers 397 Defining the Controller: The IController Interface 397 The ControllerBase Abstract Base Class 398 The Controller Class and Actions 399 Action Methods 401 The ActionResult 401 ftoc.indd xxvftoc.indd xxv 9/11/2012 2:59:45 PM9/11/2012 2:59:45 PM
  27. 27. xxvi CONTENTS Action Result Helper Methods 402 Action Result Types 404 Implicit Action Results 408 Action Invoker 410 How an Action Is Mapped to a Method 410 Invoking Actions 414 Using Asynchronous Controller Actions 414 Choosing Synchronous versus Asynchronous Pipelines 416 Writing Asynchronous Action Methods 416 Performing Multiple Parallel Operations 417 MVC 2 and 3 Using AsyncController 419 Summary 421 CHAPTER 16: REAL-WORLD ASP.NET MVC: BUILDING THE NUGET.ORG WEBSITE 423 May the Source Be with You 424 WebActivator 425 ASP.NET Dynamic Data 426 Exception Logging 430 Profiling 431 Data Access 434 EF Code-Based Migrations 434 Membership 436 Other Useful NuGet Packages 438 T4MVC 438 WebBackgrounder 438 Lucene.NET 439 AnglicanGeek.MarkdownMailer 439 Ninject 440 Summary 440 INDEX 443 ftoc.indd xxviftoc.indd xxvi 9/11/2012 2:59:45 PM9/11/2012 2:59:45 PM
  28. 28. FOREWORD I’m thrilled to introduce this book covering the latest release of ASP.NET MVC, written by an outstanding team of authors. They are my friends, but more importantly, they are fantastic technologists. Phil Haack was the Program Manager ASP.NET MVC from the very start. With a background rooted in community and open source, I count him not only as an amazing technologist but also a close friend. While at Microsoft, Phil also worked on a new .NET Package Manager called NuGet. Brad Wilson is not only my favorite skeptic but also a talented Developer at Microsoft working on ASP.NET MVC. From Dynamic Data to Data Annotations to Testing and more, there’s no end to Brad’s knowledge as a programmer. He’s worked on many open source projects, such as XUnit .NET, and continues to push people both inside and outside Microsoft towards the light. Jon Galloway is a Technical Evangelist at Microsoft focused on Azure and ASP.NET. In that role, he’s had the opportunity to work with thousands of developers who are both new to and experi- enced with ASP.NET MVC. He’s the author of the MVC Music Store tutorial, which has helped hundreds of thousands of new developers write their first ASP.NET MVC applications. Jon also helped organize mvcConf and aspConf — a series of free, online conferences for ASP.NET develop- ers. His interactions with the diverse ASP.NET community give him some great insights on how developers can begin, learn, and master ASP.NET MVC. And last but not least, K. Scott Allen rounds out the group, not just because of his wise decision to use his middle name to sound smarter, but also because he brings his experience and wisdom as a world-renowned trainer. Scott Allen is a member of the Pluralsight technical staff and has worked on websites for Fortune 50 companies, as well as consulted with startups. He is kind, thoughtful, respected, and above all, knows his stuff backwards and forwards. These fellows have teamed up to take this ASP.NET MVC 4 book to the next level, as the ASP.NET web development platform continues to grow. The platform currently is used by millions of devel- opers worldwide. A vibrant community supports the platform, both online and offline; the online forums at www.asp.net average thousands of questions and answers a day. ASP.NET and ASP.NET MVC 4 power news sites, online retail stores, and perhaps your favorite social networking site. Your local sports team, book club, or blog uses ASP.NET MVC 4, as well. When it was introduced, ASP.NET MVC broke a lot of ground. Although the pattern was old, it was new to many in the existing ASP.NET community; it walked a delicate line between productiv- ity and control, power and flexibility. Today, to me, ASP.NET MVC 4 represents choice — your choice of language, your choice of frameworks, your choice of open source libraries, your choice of patterns. Everything is pluggable. MVC 4 epitomizes absolute control of your environment — if you like something, use it; if you don’t like something, change it. You can unit test how you want, create components as you want, and use your choice of JavaScript framework. flast.indd xxviiflast.indd xxvii 9/11/2012 3:00:19 PM9/11/2012 3:00:19 PM
  29. 29. ASP.NET MVC 4 brings you a new ASP.NET Web API (a new framework for building HTTP services), updated default project templates that leverage modern web standards, solid mobile web application support, enhanced support for asynchronous methods, and more. Just as exciting, the ASP.NET MVC code is now released under an open source license that accepts contributions from the developer community. Perhaps code you write will ship with the next version of ASP.NET MVC! I encourage you to visit www.asp.net/mvc for fresh content, new samples, vid- eos, and tutorials. We all hope this book, and the knowledge within, represents the next step for you in your mastery of ASP.NET MVC 4. — Scott Hanselman Principal Community Architect Azure Web Team Microsoft flast.indd xxviiiflast.indd xxviii 9/11/2012 3:00:19 PM9/11/2012 3:00:19 PM
  30. 30. INTRODUCTION IT’S A GREAT TIME TO BE an ASP.NET developer! Whether you’ve been developing with ASP.NET for years or are just getting started, now is a great time to dig into ASP.NET MVC 4. ASP.NET MVC has been a lot of fun to work with from the start, but the last two releases have added many features that make the entire development process really enjoyable. ASP.NET MVC 3 brought features like the Razor view engine, integration with the NuGet package management system, and built-in integration with jQuery to simplify Ajax development. ASP .NET MVC 4 continues that trend, with a refreshed visual design, mobile web support, easier HTTP services using ASP.NET Web API, easier integration with popular sites with built-in OAuth support, and more. The combined effect is that you can get started quickly with full-featured web applications. This isn’t just drag-and-drop short-term productivity, either. It’s all built on a solid, patterns-based web framework that gives you total control over every aspect of your application, when you want it. Join us for a fun, informative tour of ASP.NET MVC 4! WHO THIS BOOK IS FOR Professional ASP.NET MVC 4 is designed to teach ASP.NET MVC, from a beginner level through advanced topics. If you are new to ASP.NET MVC, this book gets you started by explaining the concepts, and then helps you apply them through plenty of hands-on code examples. The authors have taught thou- sands of developers how to get started with ASP.NET MVC and know how to cut through boring rhetoric to get you up and running quickly. We understand that many of our readers are familiar with ASP.NET Web Forms, so in some places we’ll point out some similarities and differences to help put things in context. It’s worth noting that ASP.NET MVC 4 is not a replacement for ASP.NET Web Forms. Many web developers have been giving a lot of attention to other web frameworks (Ruby on Rails, Django, several PHP frameworks, etc.) that have embraced the MVC (Model-View-Controller) application pattern. If you’re one of those developers, or even if you’re just curious, this book is for you. We’ve worked hard to make sure that this book is valuable for developers who are experienced with ASP.NET MVC, as well. Throughout the book, we explain how things are designed and how best to use them. We’ve added in-depth coverage of new features, including a new chapter on ASP. NET Web API. Finally, we’ve included a new chapter by Phil Haack that shows how he and other advanced ASP.NET MVC developers build real-world, high-volume ASP.NET MVC websites with a case study of the NuGet Gallery website. flast.indd xxixflast.indd xxix 9/11/2012 3:00:19 PM9/11/2012 3:00:19 PM
  31. 31. xxx INTRODUCTION HOW THIS BOOK IS STRUCTURED This book is divided into two very broad sections, each comprising several chapters. The first half of the book is concerned with introducing the MVC pattern and how ASP.NET MVC implements that pattern. Chapter 1, “Getting Started,” helps you get started with ASP.NET MVC 3 development. It explains what ASP.NET MVC is and how ASP.NET MVC 4 fits in with the previous two releases. Then, after making sure you have the correct software installed, you’ll begin creating a new ASP.NET MVC 4 application. Chapter 2, “Controllers,” explains the basics of controllers and actions. You’ll start with some very basic “hello world” examples, and then build up to pull information from the URL and return it to the screen. Chapter 3, “Views,” explains how to use view templates to control the visual representation of the output from your controller actions. You’ll learn all about the Razor view engine, including syntax and features to help keep your views organized and consistent. Chapter 4, “Models,” teaches you how to use models to pass information from controller to view and how to integrate your model with a database (using Code-First development with Entity Framework). Chapter 5, “Forms and HTML Helpers,” dives deeper into editing scenarios, explaining how forms are handled in ASP.NET MVC. You’ll also learn how to use HTML helpers to keep your views lean. Chapter 6, “Data Annotations and Validation,” explains how to use attributes to define rules for how your models will be displayed, edited, and validated. Chapter 7, “Membership, Authorization, and Security,” teaches you how to secure your ASP.NET MVC application, pointing out common security pitfalls and how you can avoid them. You’ll learn how to leverage the ASP.NET membership and authorization features within ASP.NET MVC appli- cations to control access. Chapter 8, “Ajax,” covers Ajax applications within ASP.NET MVC applications, with special emphasis on jQuery and jQuery plug-ins. You’ll learn how to use ASP.NET MVC’s Ajax helpers and how to work effectively with the jQuery-powered validation system. Chapter 9, “Routing,” digs deep into the routing system that manages how URLs are mapped to controller actions. Chapter 10, “NuGet,” introduces you to the NuGet package management system. You’ll learn how it relates to ASP.NET MVC, how to install it, and how to use it to install, update, and create new packages. Chapter 11, “ASP.NET Web API,” shows how to create HTTP services using the new ASP.NET Web API. Chapter 12, “Dependency Injection,” explains dependency injection and shows how you can lever- age it in your applications. flast.indd xxxflast.indd xxx 9/11/2012 3:00:19 PM9/11/2012 3:00:19 PM
  32. 32. xxxi INTRODUCTION Chapter 13, “Unit Testing,” teaches you how to practice test-driven development in your ASP.NET applications, offering helpful tips on how to write effective tests. Chapter 14, “Extending MVC,” dives into the extensibility points in ASP.NET MVC, showing how you can extend the framework to fit your specific needs. Chapter 15, “Advanced Topics,” looks at advanced topics that might have blown your mind before reading the first 14 chapters of the book. It covers sophisticated scenarios in Razor, scaffolding, routing, templating, and controllers. Chapter 16, “Real-World ASP.NET MVC: Building the NuGet.org Website,” puts everything in per- spective with a case study covering the NuGet Gallery website (http://nuget.org). You’ll see how Phil Haack and other top ASP.NET developers handled things like testing, membership, deploy- ment, and data migration when they needed to build a high-performance site on ASP.NET MVC. WHAT YOU NEED TO USE THIS BOOK To use ASP.NET MVC 4, you’ll probably want a copy of Visual Studio. You can use Microsoft Visual Studio Express 2012 for Web or any of the paid versions of Visual Studio 2012 (such as Visual Studio 2012 Professional). Visual Studio 2012 includes ASP.NET MVC 4. Visual Studio and Visual Studio Express are available from the following locations: ‰ Visual Studio: www.microsoft.com/vstudio ‰ Visual Studio Express: www.microsoft.com/express/ You can also use ASP.NET MVC 4 with Visual Studio 2010 SP1. ASP.NET MVC 4 is a separate installation for Visual Studio 2010, available at the following location: ‰ ASP.NET MVC 4: www.asp.net/mvc Chapter 1 reviews the software requirements in depth, showing how to get everything set up on both your development and server machines. CONVENTIONS To help you get the most from the text and keep track of what’s happening, we’ve used a number of conventions throughout the book. PRODUCT TEAM ASIDE Boxes like this one hold tips, tricks, and trivia from the ASP.NET Product Team or some other information that is directly relevant to the surrounding text. flast.indd xxxiflast.indd xxxi 9/11/2012 3:00:20 PM9/11/2012 3:00:20 PM
  33. 33. xxxii INTRODUCTION NOTE Tips, hints, and tricks related to the current discussion are offset and placed in italics like this. As for styles in the text: ‰ We italicize new terms and important words when we introduce them. ‰ We show keyboard strokes like this: Ctrl+A. ‰ We show filenames, URLs, and code within the text like so: persistence.properties. ‰ We present code in two different ways: We use a monofont type with no highlighting for most code examples. We use bold to emphasize code that is particularly important in the present context or to show changes from a previous code snippet. SOURCE CODE Throughout the book you’ll notice places where we suggest that you install a NuGet package to try out some sample code. Install-Package SomePackageName NuGet is a package manager for .NET and Visual Studio written by the Outercurve Foundation and incorporated by Microsoft into ASP.NET MVC. Rather than having to search around for zip files on the Wrox website for source code samples, you can use NuGet to easily add these files into an ASP.NET MVC application from the convenience of Visual Studio. We think this will make it much easier and painless to try out the samples. Chapter 10 explains the NuGet system in greater detail. If you would like to download these NuGet packages for later use without an Internet connection, they are also available for download at www.wrox.com. Once at the site, simply locate the book’s title (use the Search box or one of the title lists) and click the Download Code link on the book’s detail page to obtain all the source code for the book. NOTE Because many books have similar titles, you may find it easiest to search by ISBN. This book’s ISBN is 978-1-118-34846-8. Once you download the code, just decompress it with your favorite compression tool. Alternately, you can go to the main Wrox code download page at www.wrox.com/dynamic/books /download.aspx to see the code available for this book and all other Wrox books. flast.indd xxxiiflast.indd xxxii 9/11/2012 3:00:20 PM9/11/2012 3:00:20 PM
  34. 34. xxxiii INTRODUCTION ERRATA We make every effort to ensure that there are no errors in the text or in the code. However, no one is perfect, and mistakes do occur. If you find an error in one of our books, like a spelling mistake or faulty piece of code, we would be very grateful for your feedback. By sending in errata you may save another reader hours of frustration and at the same time you will be helping us provide even higher quality information. To find the errata page for this book, go to www.wrox.com and locate the title using the Search box or one of the title lists. Then, on the book details page, click the Errata link. On this page you can view all errata that has been submitted for this book and posted by Wrox editors. A complete book list, including links to each book’s errata, is also available at www.wrox.com/misc-pages /booklist.shtml. If you don’t spot “your” error on the Errata page, go to www.wrox.com/contact/techsupport .shtml and complete the form there to send us the error you have found. We’ll check the information and, if appropriate, post a message to the book’s errata page and fix the problem in subsequent editions of the book. P2P.WROX.COM For author and peer discussion, join the P2P forums at p2p.wrox.com. The forums are a web-based system for you to post messages relating to Wrox books and related technologies and interact with other readers and technology users. The forums offer a subscription feature to e-mail you topics of interest of your choosing when new posts are made to the forums. Wrox authors, editors, other industry experts, and your fellow readers are present on these forums. At http://p2p.wrox.com you will find a number of different forums that will help you not only as you read this book, but also as you develop your own applications. To join the forums, just follow these steps: 1. Go to p2p.wrox.com and click the Register link. 2. Read the terms of use and click Agree. 3. Complete the required information to join, as well as any optional information you wish to provide, and click Submit. 4. You will receive an e-mail with information describing how to verify your account and com- plete the joining process. NOTE You can read messages in the forums without joining P2P, but in order to post your own messages, you must join. flast.indd xxxiiiflast.indd xxxiii 9/11/2012 3:00:20 PM9/11/2012 3:00:20 PM
  35. 35. xxxiv INTRODUCTION Once you join, you can post new messages and respond to messages other users post. You can read messages at any time on the Web. If you would like to have new messages from a particular forum e-mailed to you, click the Subscribe to this Forum icon by the forum name in the forum listing. For more information about how to use the Wrox P2P, be sure to read the P2P FAQs for answers to questions about how the forum software works as well as many common questions specific to P2P and Wrox books. To read the FAQs, click the FAQ link on any P2P page. flast.indd xxxivflast.indd xxxiv 9/11/2012 3:00:20 PM9/11/2012 3:00:20 PM
  36. 36. 1Getting Started Jon Galloway WHAT’S IN THIS CHAPTER? ‰ Understanding ASP.NET MVC ‰ An overview of ASP.NET MVC 4 ‰ Creating MVC 4 applications ‰ How MVC applications are structured This chapter gives you a quick introduction to ASP.NET MVC, explains how ASP.NET MVC 4 fits into the ASP.NET MVC release history, summarizes what’s new in ASP .NET MVC 4, and shows you how to set up your development environment to build ASP.NET MVC 4 applications. This is a Professional Series book about a version 4 web framework, so we’re going to keep the introductions short. We’re not going to spend any time convincing you that you should learn ASP.NET MVC. We’re assuming that you’ve bought this book for that reason, and that the best proof of software frameworks and patterns is in showing how they’re used in real-world scenarios. A QUICK INTRODUCTION TO ASP.NET MVC ASP.NET MVC is a framework for building web applications that applies the general Model View Controller pattern to the ASP.NET framework. Let’s break that down by first looking at how ASP.NET MVC and the ASP.NET framework are related. c01.indd 1c01.indd 1 9/11/2012 2:52:51 PM9/11/2012 2:52:51 PM
  37. 37. 2 x CHAPTER 1 GETTING STARTED How ASP.NET MVC Fits in with ASP.NET When ASP.NET 1.0 was first released in 2002, it was easy to think of ASP.NET and Web Forms as one and the same thing. ASP.NET has always supported two layers of abstraction, though: ‰ System.Web.UI: The Web Forms layer, comprising server controls, ViewState, and so on ‰ System.Web: The plumbing, which supplies the basic web stack, including modules, han- dlers, the HTTP stack, and so on The mainstream method of developing with ASP.NET included the whole Web Forms stack — taking advantage of drag-and-drop server controls and semi-magical statefulness, while dealing with the complications behind the scenes (an often confusing page life cycle, less than optimal HTML that was difficult to customize, and so on). However, there was always the possibility of getting below all that — responding directly to HTTP requests, building out web frameworks just the way you wanted them to work, crafting beautiful HTML — using handlers, modules, and other handwritten code. You could do it, but it was painful; there just wasn’t a built-in pattern that supported any of those things. It wasn’t for lack of patterns in the broader computer science world, though. By the time ASP.NET MVC was announced in 2007, the MVC pattern was becoming one of the most popular ways of building web frameworks. The MVC Pattern Model-View-Controller (MVC) has been an important architectural pattern in computer science for many years. Originally named Thing-Model-View-Editor in 1979, it was later simplified to Model- View-Controller. It is a powerful and elegant means of separating concerns within an application (for example, separating data access logic from display logic) and applies itself extremely well to web applications. Its explicit separation of concerns does add a small amount of extra complexity to an application’s design, but the extraordinary benefits outweigh the extra effort. It has been used in dozens of frameworks since its introduction. You’ll find MVC in Java and C++, on Mac and on Windows, and inside literally dozens of frameworks. The MVC separates the user interface (UI) of an application into three main aspects: ‰ The Model: A set of classes that describes the data you’re working with as well as the busi- ness rules for how the data can be changed and manipulated ‰ The View: Defines how the application’s UI will be displayed ‰ The Controller: A set of classes that handles communication from the user, overall applica- tion flow, and application-specific logic MVC AS A USER INTERFACE PATTERN Notice that we’ve referred to MVC as a pattern for the UI. The MVC pattern pres- ents a solution for handling user interaction, but says nothing about how you will handle other application concerns like data access, service interactions, etc. It’s helpful to keep this in mind as you approach MVC: It is a useful pattern, but likely one of many patterns you will use in developing an application. c01.indd 2c01.indd 2 9/11/2012 2:52:53 PM9/11/2012 2:52:53 PM
  38. 38. A Quick Introduction to ASP.NET MVC x 3 MVC as Applied to Web Frameworks The MVC pattern is used frequently in web programming. With ASP.NET MVC, it’s translated roughly as: ‰ Models: These are the classes that represent the domain you are interested in. These domain objects often encapsulate data stored in a database as well as code used to manipulate the data and enforce domain-specific business logic. With ASP.NET MVC, this is most likely a Data Access Layer of some kind, using a tool like Entity Framework or NHibernate com- bined with custom code containing domain-specific logic. ‰ View: This is a template to dynamically generate HTML. We cover more on that in Chapter 3 when we dig into views. ‰ Controller: This is a special class that manages the relationship between the View and the Model. It responds to user input, talks to the Model, and decides which view to render (if any). In ASP.NET MVC, this class is conventionally denoted by the suffix Controller. NOTE It’s important to keep in mind that MVC is a high-level architectural pattern, and its application varies depending on use. ASP.NET MVC is contex- tualized both to the problem domain (a stateless web environment) and the host system (ASP.NET). Occasionally I talk to developers who have used the MVC pattern in very dif- ferent environments, and they get confused, frustrated, or both (confustrated?) because they assume that ASP.NET MVC works the exact same way it worked in their mainframe account processing system 15 years ago. It doesn’t, and that’s a good thing — ASP.NET MVC is focused on providing a great web develop- ment framework using the MVC pattern and running on the .NET platform, and that contextualization is part of what makes it great. ASP.NET MVC relies on many of the same core strategies that the other MVC platforms use, plus it offers the benefits of compiled and managed code and exploits newer .NET language features, such as lambdas and dynamic and anonymous types. At its heart, though, ASP.NET applies the fundamental tenets found in most MVC-based web frameworks: ‰ Convention over configuration ‰ Don’t repeat yourself (aka the “DRY” principle) ‰ Pluggability wherever possible ‰ Try to be helpful, but if necessary, get out of the developer’s way The Road to MVC 4 In the three short years since ASP.NET MVC 1 was released in March 2009, we’ve seen four major releases of ASP.NET MVC and several more interim releases. In order to understand ASP.NET c01.indd 3c01.indd 3 9/11/2012 2:52:53 PM9/11/2012 2:52:53 PM
  39. 39. 4 x CHAPTER 1 GETTING STARTED MVC 4, it’s important to understand how we got here. This section describes the contents and back- ground of each of the three major ASP.NET MVC releases. ASP.NET MVC 1 Overview In February 2007, Scott Guthrie (“ScottGu”) of Microsoft sketched out the core of ASP.NET MVC while flying on a plane to a conference on the East Coast of the United States. It was a simple appli- cation, containing a few hundred lines of code, but the promise and potential it offered for parts of the Microsoft web developer audience was huge. As the legend goes, at the Austin ALT.NET conference in October 2007 in Redmond, Washington, ScottGu showed a group of developers “this cool thing I wrote on a plane” and asked if they saw the need and what they thought of it. It was a hit. In fact, many people were involved with the original prototype, codenamed Scalene. Eilon Lipton e-mailed the first prototype to the team in September 2007, and he and ScottGu bounced prototypes, code, and ideas back and forth. Even before the official release, it was clear that ASP.NET MVC wasn’t your standard Microsoft product. The development cycle was highly interactive: There were nine preview releases before the official release, unit tests were made available, and the code shipped under an open source license. All these highlighted a philosophy that placed a high value on community interaction throughout the development process. The end result was that the official MVC 1.0 release — including code and unit tests — had already been used and reviewed by the developers who would be using it. ASP.NET MVC 1.0 was released on 13 March 2009. ASP.NET MVC 2 Overview ASP.NET MVC 2 was released just one year later, in March 2010. Some of the main features in MVC 2 included: ‰ UI helpers with automatic scaffolding with customizable templates ‰ Attribute-based model validation on both client and server ‰ Strongly typed HTML helpers ‰ Improved Visual Studio tooling There were also lots of API enhancements and “pro” features, based on feedback from developers building a variety of applications on ASP.NET MVC 1, such as: ‰ Support for partitioning large applications into areas ‰ Asynchronous controllers support ‰ Support for rendering subsections of a page/site using Html.RenderAction ‰ Lots of new helper functions, utilities, and API enhancements One important precedent set by the MVC 2 release was that there were very few breaking changes. I think this is a testament to the architectural design of ASP.NET MVC, which allows for a lot of extensibility without requiring core changes. c01.indd 4c01.indd 4 9/11/2012 2:52:53 PM9/11/2012 2:52:53 PM
  40. 40. A Quick Introduction to ASP.NET MVC x 5 ASP.NET MVC 3 Overview ASP.NET MVC 3 shipped just 10 months after MVC 2, driven by the release date for Web Matrix. Some of the top features in MVC 3 included: ‰ The Razor view engine ‰ Support for .NET 4 Data Annotations ‰ Improved model validation ‰ Greater control and flexibility with support for dependency resolution and global action filters ‰ Better JavaScript support with unobtrusive JavaScript, jQuery Validation, and JSON binding ‰ Use of NuGet to deliver software and manage dependencies throughout the platform Since these MVC 3 features are relatively recent and are pretty important, we’ll go through them in a little more detail. NOTE This feature summary is included for developers with previous MVC experience who are anxious to hear what’s changed in the newer versions. If you’re new to ASP.NET MVC, don’t be concerned if some of these features don’t make a lot of sense right now; we’ll be covering them in a lot more detail throughout the book. You’re welcome to skip over them now and come back to this chapter later. Razor View Engine Razor is the first major update to rendering HTML since ASP.NET 1 shipped almost a decade ago. The default view engine used in MVC 1 and 2 was commonly called the Web Forms view engine, because it uses the same ASPX/ASCX/MASTER files and syntax used in Web Forms. It works, but it was designed to support editing controls in a graphical editor, and that legacy shows. An example of this syntax in a Web Forms page is shown here: <%@ Page Language="C#" MasterPageFile="</Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<MvcMusicStore.ViewModels.StoreBrowseViewModel>" %> <asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server"> Browse Albums </asp:Content> <asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server"> <div class="genre"> <h3><em><%: Model.Genre.Name %></em> Albums</h3> c01.indd 5c01.indd 5 9/11/2012 2:52:53 PM9/11/2012 2:52:53 PM
  41. 41. 6 x CHAPTER 1 GETTING STARTED <ul id="album-list"> <% foreach (var album in Model.Albums) { %> <li> <a href="<%: Url.Action("Details", new { id = album.AlbumId }) %>"> <img alt="<%: album.Title %>" src="<%: album.AlbumArtUrl %>" /> <span><%: album.Title %></span> </a> </li> <% } %> </ul> </div> </asp:Content> Razor was designed specifically as a view engine syntax. It has one main focus: code-focused tem- plating for HTML generation. Here’s how that same markup would be generated using Razor: @model MvcMusicStore.Models.Genre @{ViewBag.Title = "Browse Albums";} <div class="genre"> <h3><em>@Model.Name</em> Albums</h3> <ul id="album-list"> @foreach (var album in Model.Albums) { <li> <a href="@Url.Action("Details", new { id = album.AlbumId })"> <img alt="@album.Title" src="@album.AlbumArtUrl" /> <span>@album.Title</span> </a> </li> } </ul> </div> The Razor syntax is easier to type, and easier to read. Razor doesn’t have the XML-like heavy syn- tax of the Web Forms view engine. We’ve talked about how working with the Razor syntax feels different. To put this in more quantifi- able terms, let’s look at some of the team’s design goals in creating the Razor syntax: ‰ Compact, expressive, and fluid: Razor’s (ahem) sharp focus on templating for HTML genera- tion yields a very minimalist syntax. This isn’t just about minimizing keystrokes — although that’s an obvious result — it’s about how easy it is to express your intent. A key example is the simplicity in transitions between markup and code. You can see this in action when writ- ing out some model properties in a loop: @foreach (var album in Model.Albums) { <li> <a href="@Url.Action("Details", new { id = album.AlbumId })"> c01.indd 6c01.indd 6 9/11/2012 2:52:53 PM9/11/2012 2:52:53 PM
  42. 42. A Quick Introduction to ASP.NET MVC x 7 <img alt="@album.Title" src="@album.AlbumArtUrl" /> <span>@album.Title</span> </a> </li> } ‰ Not a new language: Razor is a syntax that lets you use your existing .NET coding skills in a template in a very intuitive way. Scott Hanselman summarized this pretty well when describ- ing his experiences learning Razor: “I kept […] going cross-eyed when I was trying to figure out what the syntax rules were for Razor until someone said stop thinking about it, just type an “at” sign and start writing code and I realize that there really is no Razor.” —HANSELMINUTES #249: ON WEBMATRIX WITH ROB CONERY http://hanselminutes.com/default.aspx?showid=268 ‰ Easy to learn: Precisely because Razor is not a new language, it’s easy to learn. You know HTML, you know .NET; just type HTML and hit the @ sign whenever you need to write some .NET code. ‰ Works with any text editor: Because Razor is so lightweight and HTML-focused, you’re free to use the editor of your choice. Visual Studio’s syntax highlighting and IntelliSense features are nice, but it’s simple enough that you can edit it in any text editor. ‰ Good IntelliSense: Though Razor was designed so that you shouldn’t need IntelliSense to work with it, IntelliSense can come in handy for things like viewing the properties your model object supports. For those cases, Razor does offer nice IntelliSense within Visual Studio, as shown in Figure 1-1. FIGURE 1-1 This is just a quick highlight of some of the reasons that Razor makes writing View code really easy. We’ll talk about Razor in a lot more depth in Chapter 3. Validation Improvements Validation is an important part of building web applications, but it’s never fun. I’ve always wanted to spend as little time as possible writing validation code, as long as I was confident that it worked correctly. c01.indd 7c01.indd 7 9/11/2012 2:52:53 PM9/11/2012 2:52:53 PM
  43. 43. 8 x CHAPTER 1 GETTING STARTED MVC 2’s attribute-driven validation system removed a lot of the pain from this process by replac- ing repetitive imperative code with declarative code. However, support was focused on a short list of top validation scenarios. There were plenty of cases where you’d get outside of the “happy path” and have to write a fair amount more code. MVC 3 extended the validation support to cover most scenar- ios you’re likely to encounter. For more information on validation in ASP.NET MVC, see Chapter 6. .NET 4 Data Annotation Support MVC 2 was compiled against .NET 3.5 and thus didn’t support any of the .NET 4 Data Annotations enhancements. MVC 3 picks up some new, very useful validation features available due to .NET 4 support. Some examples include: ‰ MVC 2’s DisplayName attribute wasn’t localizable, whereas the .NET 4 standard System .ComponentModel.DataAnnotations Display attribute is. ‰ ValidationAttribute was enhanced in .NET 4 to better work with the validation context for the entire model, greatly simplifying cases like validators that compare or otherwise reference two model properties. Streamlined Validation with Improved Model Validation MVC 3’s support for the .NET 4 IValidatableObject interface deserves individual recognition. You can extend your model validation in just about any conceivable way by implementing this inter- face on your model class and implementing the Validate method, as shown in the following code: public class VerifiedMessage : IValidatableObject { public string Message { get; set; } public string AgentKey { get; set; } public string Hash { get; set; } public IEnumerable<ValidationResult> Validate( ValidationContext validationContext) { if (SecurityService.ComputeHash(Message, AgentKey) != Hash) yield return new ValidationResult("Agent compromised"); } } Unobtrusive JavaScript Unobtrusive JavaScript is a general term that conveys a general philosophy, similar to the term REST (Representational State Transfer). The high-level description is that unobtrusive JavaScript doesn’t intermix JavaScript code in your page markup. For example, rather than hooking in via event attributes like onclick and onsubmit, the unobtrusive JavaScript attaches to elements by their ID or class, often based on the presence of other attributes (such as HTML5 data- attributes). Unobtrusive JavaScript makes a lot of sense when you consider that your HTML document is just that — a document. It’s got semantic meaning, and all of it — the tag structure, element attributes, and so on — should have a precise meaning. Strewing JavaScript gunk across the page to facilitate interaction (I’m looking at you, __doPostBack!) harms the content of the document. MVC 3 added support for unobtrusive JavaScript in two ways: ‰ Ajax helpers (such as Ajax.ActionLink and Ajax.BeginForm) render clean markup for the FORM tag, wiring up behavior leveraging extensible attributes (data- attributes) and jQuery. c01.indd 8c01.indd 8 9/11/2012 2:52:53 PM9/11/2012 2:52:53 PM
  44. 44. A Quick Introduction to ASP.NET MVC x 9 ‰ Ajax validation no longer emits the validation rules as a (sometimes large) block of JSON data, instead writing out the validation rules using data- attributes. While technically I con- sidered MVC 2’s validation system to be rather unobtrusive, the MVC 3 system is that much more — the markup is lighter weight, and the use of data- attributes makes it easier to lever- age and reuse the validation information using jQuery or other JavaScript libraries. jQuery Validation MVC 2 shipped with jQuery, but used Microsoft Ajax for validation. MVC 3 completed the transi- tion to using jQuery for Ajax support by converting the validation support to run on the popular jQuery Validation plugin. The combination of Unobtrusive JavaScript support (discussed previously) and jQuery validation using the standard plugin system means that the validation is both extremely flexible and can benefit from the huge jQuery community. Client-side validation was turned on by default for MVC 3 projects, and can be enabled site-wide with a web.config setting or by code in global.asax for upgraded projects. JSON Binding MVC 3 included JavaScript Object Notation (JSON) binding support via the new JsonValueProviderFactory, enabling your action methods to accept and model-bind data in JSON format. This is especially useful in advanced Ajax scenarios like client templates and data binding that need to post data back to the server. Dependency Resolution MVC 3 introduced a new concept called a dependency resolver, which greatly simplified the use of dependency injection in your applications. This made it easier to decouple application components, making them more configurable and easier to test. Support was added for the following scenarios: ‰ Controllers (registering and injecting controller factories, injecting controllers) ‰ Views (registering and injecting view engines, injecting dependencies into view pages) ‰ Action filters (locating and injecting filters) ‰ Model binders (registering and injecting) ‰ Model validation providers (registering and injecting) ‰ Model metadata providers (registering and injecting) ‰ Value providers (registering and injecting) This is a big enough topic that we’ve devoted an entire new chapter (Chapter 12) to it. Global Action Filters MVC 2 action filters gave you hooks to execute code before or after an action method ran. They were implemented as custom attributes that could be applied to controller actions or to an entire controller. MVC 2 included some filters in the box, like the Authorize attribute. MVC 3 extended this with global action filters, which apply to all action methods in your applica- tion. This is especially useful for application infrastructure concerns like error handling and logging. c01.indd 9c01.indd 9 9/11/2012 2:52:53 PM9/11/2012 2:52:53 PM
  45. 45. 10 x CHAPTER 1 GETTING STARTED MVC 4 Overview The MVC 4 release is building on a pretty mature base and is able to focus on some more advanced scenarios. Some top features include: ‰ ASP.NET Web API ‰ Enhancements to default project templates ‰ Mobile project template using jQuery Mobile ‰ Display Modes ‰ Task support for Asynchronous Controllers ‰ Bundling and minification The following sections provide an overview of these features. We’ll be going into them in more detail throughout the book. ASP.NET Web API ASP.NET MVC was designed for creating websites. Throughout the platform are obvious design decisions that indicate the assumed usage: responding to requests from browsers and returning HTML. However, ASP.NET MVC made it really easy to control the response down to the byte, and the MVC pattern was really useful in creating a service layer. ASP.NET developers found that they could use it to create web services that returned XML, JSON, or other non-HTML formats, and it was a lot easier than grappling with other service frameworks, such as Windows Communication Foundation (WCF), or writing raw HTTP handlers. It still had some quirks, as you were using a website framework to deliver services, but many found that it was better than the alternatives. MVC 4 includes a better solution: ASP.NET Web API (referred to as Web API), a framework that offers the ASP.NET MVC development style but is tailored to writing HTTP services. This includes both modifying some ASP.NET MVC concepts to the HTTP service domain and supplying some new service-oriented features. Here are some of the Web API features that are similar to MVC, just adapted for the HTTP service domain: ‰ Routing: ASP.NET Web API uses the same routing system for mapping URLs to controller actions. It contextualizes the routing to HTTP services by mapping HTTP verbs to actions by convention, which both makes the code easier to read and encourages following RESTful service design. ‰ Model binding and validation: Just as MVC simplifies the process of mapping input values (form fields, cookies, URL parameters, etc.) to model values, Web API automatically maps HTTP request values to models. The binding system is extensible and includes the same attri- bute-based validation that you use in MVC model binding. c01.indd 10c01.indd 10 9/11/2012 2:52:53 PM9/11/2012 2:52:53 PM
  46. 46. A Quick Introduction to ASP.NET MVC x 11 ‰ Filters: MVC uses filters (discussed in Chapter 15) to allow for adding behaviors to actions via attributes. For instance, adding an [Authorize] attribute to an MVC action will prohibit anonymous access, automatically redirecting to the login page. Web API also supports some of the standard MVC filters (like a service-optimized [Authorize] attribute) and custom filters. ‰ Scaffolding: You add new Web API controllers using the same dialog used to add an MVC controller (as described later this chapter). You have the option to use the Add Controller dia- log to quickly scaffold a Web API controller based on an Entity Framework–based model type. ‰ Easy unit testability: Much like MVC, Web API is built around the concepts of dependency injection and avoiding the use of global state. Web API also adds some new concepts and features specific to HTTP service development: ‰ HTTP programming model: The Web API development experience is optimized for working with HTTP requests and responses. There’s a strongly typed HTTP object model, HTTP sta- tus codes and headers are easily accessible, etc. ‰ Action dispatching based on HTTP verbs: In MVC the dispatching of action methods is based on their names. In Web API methods can be automatically dispatched based on the HTTP verb. So, for example, a GET request would be automatically dispatched to a control- ler action named GetItem. ‰ Content negotiation: HTTP has long supported a system of content negotiation, in which browsers (and other HTTP clients) indicate their response format preferences, and the server responds with the highest preferred format that it can support. This means that your con- troller can supply XML, JSON, and other formats (you can add your own), responding to whichever the client most prefers. This allows you to add support for new formats without having to change any of your controller code. ‰ Code-based configuration: Service configuration can be complex. Unlike WCF’s verbose and complex configuration file approach, Web API is configured entirely via code. Although ASP.NET Web API is included with MVC 4, it can be used separately. In fact, it has no dependencies on ASP.NET at all, and can be self-hosted — that is, hosted outside of ASP.NET and IIS. This means you can run Web API in any .NET application, including a Windows Service or even a simple console application. For a more detailed look at ASP.NET Web API, see Chapter 11. Enhancements to Default Project Templates The visual design of the default template for MVC 1 projects had gone essentially unchanged through MVC 3. When you created a new MVC project and ran it, you got a white square on a blue background, as shown in Figure 1-2. (The blue doesn’t show in this black and white book, but you get the idea.) In MVC 4, both the HTML and CSS for the default template have been completely redesigned. A new MVC application appears as shown in Figure 1-3. c01.indd 11c01.indd 11 9/11/2012 2:52:53 PM9/11/2012 2:52:53 PM
  47. 47. 12 x CHAPTER 1 GETTING STARTED FIGURE 1-2 FIGURE 1-3 c01.indd 12c01.indd 12 9/11/2012 2:52:53 PM9/11/2012 2:52:53 PM
  48. 48. A Quick Introduction to ASP.NET MVC x 13 In addition to a more modern design (or, some would say, any thought to design at all), the new template also features support for mobile browsers through adaptive layout. Adaptive layout is a technique for designing fluid web layouts that respond to differing screen dimensions through CSS media queries. When the site is viewed at lower than 850px width (such as on a phone or tablet), the CSS automatically reconfigures to optimize for the small form factor, as shown in the mobile emulator in Figure 1-4. While your sites deserve their own custom design, it’s nice that the underlying HTML and CSS in an MVC 4 project are set up using modern markup and CSS that responds well to the growing mobile browser viewership. Mobile Project Template Using jQuery Mobile If you’re going to be creating sites that will only be viewed in mobile browsers, you can make use of the new Mobile Project template. This template preconfigures your site to use the popular jQuery Mobile library, which provides styles that look good and work well on mobile devices, as shown in Figure 1-5. jQuery Mobile is touch optimized, supports Ajax navigation, and uses progressive enhancement to support mobile device features. FIGURE 1-4 FIGURE 1-5 c01.indd 13c01.indd 13 9/11/2012 2:52:54 PM9/11/2012 2:52:54 PM
  49. 49. 14 x CHAPTER 1 GETTING STARTED Display Modes Display modes use a convention-based approach to allow selecting different views based on the browser making the request. The default view engine first looks for views with names ending with .Mobile.cshtml when the browser’s user agent indicates a known mobile device. For example, if you have a generic view titled Index.cshtml and a mobile view titled Index.Mobile.cshtml, MVC 4 will automatically use the mobile view when viewed in a mobile browser. Additionally, you can register your own custom device modes that will be based on your own cus- tom criteria — all in just one code statement. For example, to register a WinPhone device mode that would serve views ending with .WinPhone.cshtml to Windows Phone devices, you’d use the follow- ing code in the Application_Start method of your Global.asax: DisplayModeProvider.Instance.Modes.Insert(0, new DefaultDisplayMode("WinPhone") { ContextCondition = (context => context.GetOverriddenUserAgent().IndexOf ("Windows Phone OS", StringComparison.OrdinalIgnoreCase) >= 0) }); Bundling and Minification ASP.NET 4 supports the same bundling and minification framework that is included in ASP.NET 4.5. This system reduces requests to your site by combining several individual script references into a single request. It also “minifies” the requests through a number of techniques, such as shorten- ing variable names and removing whitespace and comments. This system works on CSS as well, bundling CSS requests into a single request and compressing the size of the CSS request to produce equivalent rules using a minimum of bytes, including advanced techniques like semantic analysis to collapse CSS selectors. The bundling system is highly configurable, allowing you to create custom bundles that contain specific scripts and reference them with a single URL. You can see some examples by referring to default bundles listed in /App_Start/BundleConfig.cs in a new MVC 4 application using the Internet template. One nice byproduct of using bundling and minification is that you can remove file references from your view code. This means that you can add or upgrade script libraries and CSS files that have different filenames without having to update your views or layout, since the references are made to script and CSS bundles rather than individual files. For example, the MVC Internet application tem- plate includes a jQuery bundle that is not tied to the version number: bundles.Add(new ScriptBundle("~/bundles/jquery").Include( "~/Scripts/jquery-{version}.js")); This is then referenced in the site layout ( _Layout.cshtml) by the bundle URL, as follows: @Scripts.Render("~/bundles/jquery") Since these references aren’t tied to a jQuery version number, updating the jQuery library (either manually or via NuGet) will be picked up automatically by the bundling and minification system without requiring any code changes. c01.indd 14c01.indd 14 9/11/2012 2:52:54 PM9/11/2012 2:52:54 PM
  50. 50. A Quick Introduction to ASP.NET MVC x 15 Included Open Source Libraries MVC project templates have long been including top open source libraries like jQuery and Modernizr. As of MVC 3, these were included via NuGet, which makes it even simpler to upgrade them and manage dependencies. MVC 4 project templates include a few new libraries: ‰ Json.NET: Json.NET is a .NET library for manipulating information in JavaScript Object Notation (JSON). It was included in MVC 4 as part of Web API to support serializing data to JSON format, allowing for data contracts, anonymous types, dynamic types, Dates, TimeSpans, object reference preservation, indenting, camel casing, and many other useful serialization features. However, you can make use of Json.NET’s additional features, includ- ing LINQ to JSON and automatic conversion from JSON to XML. ‰ DotNetOpenAuth: MVC uses DotNetOpenAuth to support OpenID- and OAuth-based log- ins using third-party identity providers. The Account Controller is set up to make it easy to add support for Facebook, Microsoft, Google, and Twitter; however, since these logins are built on top of OpenID and OAuth, you can easily plug in additional providers. While you can use the DotNetOpenAuth classes directly, MVC 4 also provides an OAuthWebSecurity (in the Microsoft.Web.WebPages.OAuth namespace) to simplify common usage. Miscellaneous Features MVC 4 includes a lot of features not listed previously. The full list is in the release notes, available at http://www.asp.net/whitepapers/mvc4-release-notes. Some of the most interesting ones that don’t fit into any of the preceding themes are listed here. ‰ Configuration logic moved to App_Start: New features are nice, but the additional logic for features that are configured via code was really starting to clutter up the Global.asax Application_Start method. These configurations have been moved to static classes in the App_Start directory. ‰ AuthConfig.cs: Used to configure security settings, including sites for OAuth login. ‰ BundleConfig.cs: Used to register bundles used by the bundling and minification system. Several bundles are added by default, including jQuery, jQueryUI, jQuery validation, Modernizr, and default CSS references. ‰ FilterConfig.cs: Unsurprisingly, this is used to register global MVC filters. The only filter registered by default is the HandleErrorAttribute, but this is a great place to put other filter registrations. ‰ RouteConfig.cs: Holds the granddaddy of the MVC config statements, Route con- figuration. Routing is discussed in detail in Chapter 9. ‰ WebApiConfig.cs: Used to register Web API routes, as well as set any additional Web API configuration settings. ‰ Empty MVC project template: MVC 4 has included an Empty project template since MVC 2, but it wasn’t really empty; it still included the folder structure, a CSS file, and more than a dozen JavaScript files. Due to popular request, that template has been renamed Basic, and the new Empty project template really is empty. c01.indd 15c01.indd 15 9/11/2012 2:52:54 PM9/11/2012 2:52:54 PM
  51. 51. 16 x CHAPTER 1 GETTING STARTED ‰ Add Controller anywhere: Previously, the Visual Studio Add Controller menu item only dis- played when you right-clicked on the Controllers folder. However, the use of the Controllers folder was purely for organization. (MVC will recognize any class that implements the IController interface as a Controller, regardless of its location in your application.) The MVC 4 Visual Studio tooling has been modified to display the Add Controller menu item for any folder in your MVC project. This allows you to organize your controllers however you would like, perhaps separating them into logical groups or separating MVC and Web API controllers. NOT APPEARING IN THIS FILM: SINGLE PAGE APPLICATION AND RECIPES The MVC 4 Beta included a few previews of interesting, experimental features that are not included in the release version of MVC 4. Both are planned to ship later as out-of-band releases. Single Page Application Single Page Application (SPA) is a new project template for building single page applications that focus mainly on client-side interactions using JavaScript and Web APIs. This kind of web application can be very interactive and efficient — think of Microsoft Outlook Web Access, Gmail, etc. — but is also significantly harder to build. The Single Page Application template included: ‰ A set of JavaScript libraries to interact with local and cached data ‰ Additional Web API components for unit of work and DAL support ‰ An MVC project template with scaffolding support to tie the pieces together This preview generated a lot of interest and feedback. Unfortunately, the team determined that they wouldn’t be able to complete it in time to ship with MVC 4, and it was removed from the MVC 4 RC. It’s still in development and planned for an out-of-band release following the MVC 4 release. Recipes Recipes make it easy to update Visual Studio tooling via NuGet packages. The team initially worked to allow extending the MVC tooling (e.g., the Add Area, Add Controller, and Add View dialogs). Phil demonstrated a View Mobilizer sample Recipe that created mobile versions of existing views with a simple checkbox dialog. However, the team realized that Recipes had a lot more potential than just extend- ing MVC tooling. A wide variety of NuGet packages could benefit from custom Visual Studio tooling to provide simplified configuration, automation, designers, etc. Based on this, Recipes was removed after the MVC 4 Beta but will be included in a future NuGet release. c01.indd 16c01.indd 16 9/11/2012 2:52:54 PM9/11/2012 2:52:54 PM
  52. 52. Creating an MVC 4 Application x 17 Open Source Release ASP.NET MVC has been under an open source license since the initial release, but it was just open source code rather than a full open source project. You could read the code; you could modify code; you could even distribute your modifications; but you couldn’t contribute your code back to the offi- cial MVC code repository. That changed with the ASP.NET Web Stack open source announcement in May 2012. This announcement marked the transition of ASP.NET MVC, ASP.NET Web Pages (including the Razor view engine), and ASP.NET Web API from open source licensed code to fully open source projects. All code changes and issue tracking for these projects is done in public code repositories, and these projects are allowed to accept community code contributions (aka pull requests) if the team agrees that the changes make sense. Even in the short time since the project has been opened, several bug fixes and feature enhancements have already been accepted into the official source and will ship with the MVC 4 release. External code submissions are reviewed and tested by the ASP.NET team, and when released will be sup- ported by Microsoft just as any previous ASP.NET MVC releases have been. Even if you’re not planning to contribute any source code, the public repository makes a huge difference in visibility. While in the past you needed to wait for interim releases to see what the team was working on, you can view source check-ins as they happen (at http://aspnetwebstack .codeplex.com/SourceControl/list/changesets) and even run nightly releases of the code to test out new features as they’re written. CREATING AN MVC 4 APPLICATION The best way to learn about how MVC 4 works is to get started with building an application, so let’s do that. Software Requirements for ASP.NET MVC 4 MVC 4 runs on the following Windows client operating systems: ‰ Windows XP ‰ Windows Vista ‰ Windows 7 ‰ Windows 8 It runs on the following server operating systems: ‰ Windows Server 2003 ‰ Windows Server 2008 ‰ Windows Server 2008 R2 c01.indd 17c01.indd 17 9/11/2012 2:52:55 PM9/11/2012 2:52:55 PM
  53. 53. 18 x CHAPTER 1 GETTING STARTED MVC 4 development tooling is included with Visual Studio 2012 and can be installed on Visual Studio 2010 SP1/Visual Web Developer 2010 Express SP1. Installing ASP.NET MVC 4 After ensuring you’ve met the basic software requirements, it’s time to install ASP.NET MVC 4 on your development and production machines. Fortunately, that’s pretty simple. SIDE-BY-SIDE INSTALLATION WITH PREVIOUS VERSIONS OF MVC MVC 4 installs side-by-side with previous versions of MVC, so you can install and start using MVC 4 right away. You’ll still be able to create and update existing MVC 1, 2, and 3 applications, as before. Installing the MVC 4 Development Components The developer tooling for ASP.NET MVC 4 supports Visual Studio 2010 and Visual Studio 2012, including the free Express versions of both products. MVC 4 is included with Visual Studio 2012, so there’s nothing to install. If you’re using Visual Studio 2010, you can install MVC 4 using either the Web Platform Installer (http://www.microsoft .com/web/gallery/install.aspx?appid=MVC4VS2010) or the executable installer package (avail- able at http://go.microsoft.com/fwlink/?LinkID=243392). I generally prefer to use the Web Platform Installer (often called the WebPI, which makes me picture it with a magnificent Tom Selleck moustache for some reason) because it downloads and installs only the components you don’t already have; the executable installer is able to run offline so it includes everything you might need, just in case. Installing MVC 4 on a Server The installers detect if they’re running on a computer without a supported development environ- ment and just install the server portion. Assuming your server has Internet access, WebPI is a lighter weight install, because there’s no need to install any of the developer tooling. When you install MVC 4 on a server, the MVC runtime assemblies are installed in the Global Assembly Cache (GAC), meaning they are available to any website running on that server. Alternatively, you can just include the necessary assemblies in your application without requiring that MVC 4 install on the server at all. In the past, this process, called bin deploy- ment, required some extra work. Prior to the MVC 3 Tools Update, you either had to manually set assemblies to Copy Local in Visual Studio or use the Include Deployable Assemblies dialog. Starting with MVC 4, all assemblies are included via NuGet references. As such, all necessary assemblies are automatically added to the bin directory, and any MVC 4 application is bin- deployable. For this reason, the Include Deployable Assemblies dialog has been removed from Visual Studio 2012. c01.indd 18c01.indd 18 9/11/2012 2:52:55 PM9/11/2012 2:52:55 PM
  54. 54. Creating an MVC 4 Application x 19 Creating an ASP.NET MVC 4 Application After installing MVC 4, you’ll have some new options in Visual Studio 2010 and Visual Web Developer 2010. The experience in both IDEs is very similar; because this is a Professional Series book we’ll be focusing on Visual Studio development, mentioning Visual Web Developer only when there are significant differences. MVC MUSIC STORE We’ll be loosely basing some of our samples on the MVC Music Store tutorial. This tutorial is available online at http://mvcmusicstore.codeplex.com and includes a 150-page e-book covering the basics of building an MVC 4 application. We’ll be going quite a bit further in this book, but it’s nice to have a common base if you need more information on the introductory topics. To create a new MVC project: 1. Begin by choosing File Í New Project, as shown in Figure 1-6. FIGURE 1-6 c01.indd 19c01.indd 19 9/11/2012 2:52:55 PM9/11/2012 2:52:55 PM
  55. 55. 20 x CHAPTER 1 GETTING STARTED 2. In the Installed Templates section on the left column of the New Project dialog, shown in Figure 1-7, select the Visual C# Í Web templates list. This displays a list of web application types in the center column. FIGURE 1-7 3. Select ASP.NET MVC 4 Web Application, name your application MvcMusicStore, and click OK. The New ASP.NET MVC 4 Dialog After creating a new MVC 4 application, you’ll be presented with an intermediate dialog with some MVC-specific options for how the project should be created, as shown in Figure 1-8. The options you select from this dialog can set up a lot of the infrastructure for your application, from account management to view engines to testing. Application Templates First, you have the option to select from several preinstalled project templates. ‰ The Internet Application template: This contains the beginnings of an MVC web application — enough so that you can run the application immediately after creating it and see a few pages. You’ll do that in just a minute. This template also includes some basic account management functions which run against the ASP.NET Membership system (as dis- cussed in Chapter 7). ‰ The Intranet Application template: The Intranet Application template was added as part of the ASP.NET MVC 3 Tools Update. It is similar to the Internet Application template, c01.indd 20c01.indd 20 9/11/2012 2:52:55 PM9/11/2012 2:52:55 PM
  56. 56. Creating an MVC 4 Application x 21 but the account management functions run against Windows accounts rather than the ASP .NET Membership system. ‰ The Basic template: This template is pretty minimal. It still has the basic folders, CSS, and MVC application infrastructure in place, but no more. Running an application created using the Empty template just gives you an error message — you need to work just to get to square one. Why include it, then? The Basic template is intended for experienced MVC developers who want to set up and configure things exactly how they want them. ‰ The Empty template: The Basic template used to be called the Empty template, but develop- ers complained that it wasn’t quite empty enough. With MVC 4, the previous Empty template was renamed Basic, and the new Empty template is about as empty as you can get. It has the assemblies and basic folder structure in place, but that’s about it. ‰ The Mobile Application template: As described earlier in this chapter, the Mobile Application template is preconfigured with jQuery Mobile to jump-start creating a mobile- only website. It includes mobile visual themes, a touch-optimized UI, and support for Ajax navigation. ‰ The Web API template: ASP.NET Web API is a framework for creating HTTP services (and is discussed in detail in Chapter 11). The Web API template is similar to the Internet Application template but is streamlined for Web API development. For instance, there is no user account management functionality, as Web API account management is often signifi- cantly different from standard MVC account management. Web API functionality is also available in the other MVC project templates, and even in non-MVC project types. FIGURE 1-8 c01.indd 21c01.indd 21 9/11/2012 2:52:55 PM9/11/2012 2:52:55 PM
  57. 57. 22 x CHAPTER 1 GETTING STARTED View Engines The next option on the New ASP.NET MVC 4 Project dialog is a View Engine drop-down. View engines offer different templating languages used to generate the HTML markup in your MVC application. Prior to MVC 3, the only built-in option was the ASPX, or Web Forms, view engine. That option is still available, as shown in Figure 1-9. FIGURE 1-9 However, MVC 3 added a new option here: the Razor view engine. We’ll be looking at that in a lot more detail, especially in Chapter 3. Testing All the built-in project templates have an option to create a unit test project with sample unit tests, as shown in Figure 1-10. FIGURE 1-10 Leaving the Create a Unit Test Project checkbox unselected means that your project will be created without any unit tests, so there’s nothing else to do. RECOMMENDATION: CHECK THE BOX I’m hoping you’ll get in the habit of checking that Create a Unit Test Project box for every project you create. I’m not going to try to sell you the Unit Testing religion — not just yet. We’ll be talking about unit testing throughout the book, especially in Chapter 12, which covers unit testing and testable patterns, but we’re not going to try to ram it down your throat. Most developers I talk to are convinced that there is value in unit testing. Those who aren’t using unit tests would like to, but they’re worried that it’s just too hard. They don’t know where to get started, they’re worried that they’ll get it wrong, and they are just kind of paralyzed. I know just how they feel; I was there. c01.indd 22c01.indd 22 9/11/2012 2:52:55 PM9/11/2012 2:52:55 PM
  58. 58. Creating an MVC 4 Application x 23 So, here’s my sales pitch: Just check the box. You don’t have to know anything to do it; you don’t need an ALT.NET tattoo or a certification. We’ll cover some unit testing in this book to get you started, but the best way to get started with unit test- ing is to just check the box, so that later you can start writing a few tests without having to set anything up. After checking the Create a Unit Test Project box, you’ll have a few more choices: ‰ The first is simple: You can change the name of your unit test project to anything you want. ‰ The second option allows you to select a test framework, as shown in Figure 1-11. You may have noticed that there’s only one test framework option shown, which doesn’t seem to make a whole lot of sense. The reason there’s a drop-down is that unit testing frameworks can regis- ter with the dialog, so if you’ve installed other unit testing frameworks (like xUnit, NUnit, MbUnit, and so on) you’ll see them in that drop-down list as well. FIGURE 1-11 NOTE The Visual Studio Unit Test Framework is available only with Visual Studio 2012 Professional and higher versions. If you are using Visual Studio 2012 Standard Edition or Express, you will need to download and install the NUnit, MbUnit, or xUnit extensions for ASP.NET MVC in order for this dialog to be shown. REGISTERING UNIT TESTING FRAMEWORKS WITH THE UNIT TESTING FRAMEWORK DROP-DOWN Ever wondered what’s involved in registering a testing framework with the MVC New Project dialog? The process is described in detail on MSDN (http://msdn.microsoft.com /en-us/library/dd381614.aspx). There are two main steps: 1. Create and install a template project for the new MVC Test Project. continues c01.indd 23c01.indd 23 9/11/2012 2:52:56 PM9/11/2012 2:52:56 PM
  59. 59. 24 x CHAPTER 1 GETTING STARTED 2. Register the test project type by adding a few registry entries under HKEY_ CURRENT_USERSoftwareMicrosoftVisualStudio10.0_ConfigMVC4 TestProjectTemplates. Of course, both of these things can be included in the installation process for a unit testing framework, but you can customize them if you’d like without a huge amount of effort. Review your settings on the New ASP.NET MVC 4 Project dialog to make sure they match Figure 1-12, and then click OK. FIGURE 1-12 This creates a solution for you with two projects — one for the web application and one for the unit tests, as shown in Figure 1-13. THE MVC APPLICATION STRUCTURE When you create a new ASP.NET MVC application with Visual Studio, it automatically adds several files and directories to the project, as shown in Figure 1-14. ASP.NET MVC projects created with the Internet application template have eight top-level directories, shown in Table 1-1. (continued) c01.indd 24c01.indd 24 9/11/2012 2:52:56 PM9/11/2012 2:52:56 PM
  60. 60. The MVC Application Structure x 25 FIGURE 1-13 FIGURE 1-14 c01.indd 25c01.indd 25 9/11/2012 2:52:56 PM9/11/2012 2:52:56 PM
  61. 61. 26 x CHAPTER 1 GETTING STARTED TABLE 1-1: Default Top-Level Directories DIRECTORY PURPOSE /Controllers Where you put Controller classes that handle URL requests /Models Where you put classes that represent and manipulate data and business objects /Views Where you put UI template files that are responsible for rendering output, such as HTML /Scripts Where you put JavaScript library files and scripts (.js) /Images Where you put images used in your site /Content Where you put CSS and other site content, other than scripts and images /Filters Where you put filter code. Filters are an advanced feature, discussed in Chapter 14. /App_Data Where you store data files you want to read/write /App_Start Where you put configuration code for features like Routing, Bundling, and Web API WHAT IF I DON’T LIKE THAT DIRECTORY STRUCTURE? ASP.NET MVC does not require this structure. In fact, developers working on large applications will typically partition the application across multiple projects to make it more manageable (for example, data model classes often go in a separate class library project from the web application). The default project structure, how- ever, does provide a nice default directory convention that you can use to keep your application concerns clean. Note the following about these files and directories. When you expand: ‰ The /Controllers directory, you’ll find that Visual Studio added two Controller classes (Figure 1-15) — HomeController and AccountController — by default to the project. ‰ The /Views directory, you’ll find that three subdirectories — /Account, /Home, and /Shared — as well as several template files within them, were also added to the project by default (Figure 1-16). ‰ The /Content and /Scripts directories, you’ll find a Site.css file that is used to style all HTML on the site, as well as JavaScript libraries that can enable jQuery support within the application (Figure 1-17). ‰ The MvcMusicStore.Tests project, you’ll find two classes that contain unit tests for your Controller classes (Figure 1-18). c01.indd 26c01.indd 26 9/11/2012 2:52:56 PM9/11/2012 2:52:56 PM
  62. 62. The MVC Application Structure x 27 FIGURE 1-15 FIGURE 1-16 These default files, added by Visual Studio, provide you with a basic structure for a working appli- cation, complete with homepage, about page, account login/logout/registration pages, and an unhandled error page (all wired up and working out of the box). ASP.NET MVC and Conventions ASP.NET MVC applications, by default, rely heavily on conventions. This allows developers to avoid having to configure and specify things that can be inferred based on convention. For instance, MVC uses a convention-based directory-naming structure when resolving View templates, and this convention allows you to omit the location path when referencing views from within a Controller class. By default, ASP.NET MVC looks for the View template file within the Views[ControllerName] directory underneath the application. MVC is designed around some sensible convention-based defaults that can be overridden as needed. This concept is commonly referred to as “convention over configuration.” c01.indd 27c01.indd 27 9/11/2012 2:52:57 PM9/11/2012 2:52:57 PM
  63. 63. 28 x CHAPTER 1 GETTING STARTED FIGURE 1-17 FIGURE 1-18 Convention over Configuration The convention over configuration concept was made popular by Ruby on Rails a few years back, and essentially means: We know, by now, how to build a web application. Let’s roll that experience into the framework so we don’t have to configure absolutely everything again. You can see this concept at work in ASP.NET MVC by taking a look at the three core directories that make the application work: ‰ Controllers ‰ Models ‰ Views You don’t have to set these folder names in the web.config file — they are just expected to be there by convention. This saves you the work of having to edit an XML file like your web.config, for c01.indd 28c01.indd 28 9/11/2012 2:52:57 PM9/11/2012 2:52:57 PM